The supported nickel catalysts based on porous nickel ribbon with MgO underlayer were tested in tri-reforming of methane to synthesis gas (1 atm, 750 °C, CH4/CO2/H2O/O2/N2 = 24/18/18/3,5/36,5, ...GHSV = 62.5 L/gh). The predominant part of the supported nickel particles in the used catalysts remain in the state of dispersed crystallites epitaxially bound to MgO. Besides, highly dispersed nickel crystallites (2–3 nm) epitaxially bound to MgO also appear. These catalysts showed stable activity throughout the test period (9 h); after the reaction no carbon formation was observed. The resistance of these catalysts to carbon formation was attributed both to the formation of nickel crystallites epitaxially bound to MgO and to the formation of the MgO underlayer that covers the nickel ribbon and prevents its contact with the reaction medium.
The investigation of in-vitro response of cell cultures derived from tumor material of individual patients with similar tumor localizations to photodynamic treatment is presented. Tumor types ...included in the research were renal cell carcinoma, melanoma and alveolar, synovial, lypo- and osteo- sarcomas. Long-term observations of treatment-induced morphological changes in cells were performed by means of digital holographic microscopy. A substantial variance in response of cells of individual patients with similar tumor types and localizations to photodynamic treatment with the same dose has been observed. These peculiarities are indicative of the demand to personalized protocols of photodynamic treatment. The elevated resistance of cells of some patients to treatment at high doses highlights potential limitations of photodynamic therapy for some patients. Digital holographic microscopy is shown to be an informative label-free noninvasive tool allowing for long-term monitoring of cell samples in vitro and providing quantitative information on necrosis rate and loss of cellular dry mass. The developed methodology can be generalized for analysis of cellular response to various therapies.
•Tumor cells of patients with the same malignancy show different response to PDT.•PDT can be inefficient for treatment of some patients.•Digital holography is informative in assessment of cells death dynamics.•Average phase shift and dry mass decrease exponentially in a course of cell necrosis.•Proliferative activity of cells does not correlate with their resistivity to PDT.
Palladium catalysts supported on nanosized CeO
2 supports were synthesized by different methods. The catalysts showed high low-temperature activity (LTA) in CO oxidation. The synthesized ...palladium–ceria catalysts for low-temperature CO oxidation were investigated by a complex of physicochemical methods, and their catalytic performance was determined in the light-off regime. It was shown using high-resolution transmission electron microscopy (HRTEM) and EDX microanalysis that the catalysts with high LTA are characterized by exceptionally high dispersity of palladium on the surface of the supports. Two different states of palladium were observed by XPS. They correspond to the surface interaction phases (SIPs) as Pd
x
CeO
2−δ and small metal clusters (<10
Å). According to diffraction images obtained by HRTEM, the latter have flattened shape due to epitaxial binding between (1
1
1) facets of palladium and CeO
2. Two types of CO adsorption sites (Pd
2+ and Pd
0) were distinguished by FTIR. They can be attributed to SIP (Pd
2+) and palladium in flat metal clusters (Pd
δ+ and Pd
0). The drop of LTA in CO oxidation is related to the loss of the palladium chemical interaction with the surface of the support and palladium sintering to form PdO nanoparticles. The formation of PdO particles is stimulated by crystallization of CeO
2 particle surface due to the calcination of support at temperatures above 600
°C. The XPS, HRTEM and FTIR data give reliable evidence that PdO particles are not responsible for LTA in CO oxidation.
In this work, the structure of the active sites consisting of two phases: atomically dispersed palladium within the SIP and palladium metal nanoclusters is proposed. The catalyst pretreatment in hydrogen was found to improve significantly its catalytic (LTA) properties. The effect of the hydrogen pretreatment was supposed to be related to the formation of hydroxyl groups and their effect on the electronic and geometrical state of the surface active sites and their possible direct participation in CO oxidation.
We consider the regularities of a plastic flow in materials with strain-induced phase transformation in titanium nickelide and trip steel as examples. The experimental analysis of plastic deformation ...processes has been carried out using the technique of digital correction of speckle images, which makes it possible to describe quantitatively the behavior of plasticity fronts associated with phase transformation in the given materials. The mechanisms of formation of the Lüders fronts as well as the Portevin–Le Chatelier fronts at different stages of the plastic flow are considered.
•The texture of MgO supported on porous metallic nickel was studied.•Dispersed MgO was formed with the use of Mg(NO3)2 as precursor.•The texture of Ni catalysts supported on Ni ribbon with MgO ...underlayer was studied.•Crystallites of supported nickel were found to be epitaxially bound with MgO.•Catalysts with MgO layer completely covering Ni ribbon were among prepared ones.
The effect of synthesis conditions on the phase composition and texture of porous nickel ribbon with a MgO underlayer and of nickel catalysts supported on it was studied. The MgO underlayer was prepared by impregnation of a nickel ribbon with a Mg(NO3)2 or Mg(CH3COO)2 water solutions and subsequent calcination at 750 °C in H2. The formation of more dispersed MgO was observed with the use of Mg(NO3)2 as precursor. Catalysts were prepared by supporting of nickel onto nickel ribbon with MgO underlayer by its impregnation with a mixture of solutions of Ni(NO3)2 and Mg(NO3)2 followed by thermal pre-treatment in N2 or in He. Under reduction the formation of highly dispersed nickel crystallites (3–5 nm) epitaxially bound to MgO was observed in the catalysts with MgO underlayer prepared from Mg(NO3)2 with thermal pre-treatment of the precursor of active component in N2 or He. The supported nickel catalysts showed stable activity in tri-reforming of methane throughout the test period (9 h).
The regularities of the formation of localized plastic flow autowaves in metals upon Lüders and Portevin–Le Chatelier deformations are considered taking into account the difference in the microscopic ...plastic flow mechanisms of these phenomena. Regularities in the development of these effects are studied. It has been established that the features of deformation characteristic for them are determined by the difference in the properties of the active media formed in the materials under study upon plastic deformation. The conditions for generating a switching autowave under Lüders deformation and an excitation autowave for the Portevin–Le Chatelier effect in deformable materials are considered.
The hydrological role of forest communities dominating in the Podkamennaya Tunguska basin has been assessed by their contribution to the total evaporation in the watershed area based on the landscape ...differentiation of the region. We have used evapotranspiration parameters obtained by remote sensing data from MODIS Global Evapotranspiration Project (MOD16 ET), which takes into account the climatic data of the studied area, the types of the terrestrial surface, and the diversity of the landcover. The studies show that the evapotranspiration of the specified classes of forest vegetation is characterized by significant variability both in space and with time. The variability of evapotranspiration from year to year is primarily related to changes in meteorological parameters and the leaf index. The evaporation variability in space is determined by general climatic characteristics of the research area and different species composition of forest stands. The analysis of data reveals the tendency to a decrease in the annual evapotranspiration in the Podkamennaya Tunguska basin from 2000 to 2014. A comparative analysis of evapotranspiration trends with those in air temperature and precipitation confirms that the evapotranspiration decrease is related to changes in climatic conditions in the studied area. It is revealed that the landscape structure of watersheds may be used to indicate the processes forming evapotranspiration as an important component of the water balance, as well as to determine the hydrologically significant boundaries of landscapes. The assessment of evaporation from the land surface based on remote sensing data (product MOD16 ET) may be used for water balance calculations in watersheds of various sizes, particularly in the absence of a runoff database.
This work is dedicated to the evaluation of the PGP (plant growth promoting) properties of
Bacillus pumilus
strain 3-19. This strain is a derivative of
Bacillus pumilus
7P, a soil isolate that has ...developed resistance to streptomycin and increased production of certain extracellular hydrolases. The investigation demonstrated that
B. pumilus
3-19 proficiently developed biofilms when cultured in liquid medium at 37°C. Siderophore production by strain 3-19 was identified on the Chrome Azurol S (CAS) agar plate, however, not in the liquid medium. The ability of
B. pumilus
strain 3-19 to accumulate of biosurfactants on different liquid media was investigated. The strain also demonstrated antimicrobial activity against phytopathogenic bacteria
Pectobacterium atrosepticum
SCRI1043 and
Xanthomonas vesicatoria
DSM22252. However, no antagonistic activity was found against the phytopathogenic micromycetes
Fusarium oxysporum
DR57 and
Alternaria solani
12RKL15 was found. Therefore, it is important to investigate the plant growth promoting properties of
Bacillus pumilus
3-19 when considering using the strain for crop protection, biofertilisers and biopesticides.
Many natural substances exhibit anti-inflammatory activity and considerable potential in prophylaxis and treatment of allergies. Knowing exact molecular targets, which is required for developing ...these as medicinal products, is often challenging for multicomponent compositions.
In the present study we examined novel polyphenolic substance, a water-soluble fraction of wood lignin (laboratory code BP-Cx-1). In our previous study, a number of polyphenolic components of BP-Cx-1 (flavonoids, sapogenins, phenanthrenes etc.) were identified as the major carriers of biological activity of BP-Cx drug family, and several molecular targets involved in cancer and/or inflammation signaling pathways were proposed based on the results of the in vitro and in silico screening studies.
In the present study, half maximal inhibitory concentration (IC50) of BP-Cx-1 was established with a radioligand method and a range of IC50 values between 22.8 and 40.3 μg/ml were obtained for adenosine receptors A1, A2A and prostaglandin receptors EP2, IP (PGI2). IC50 for serotonin 5-HT1 and for glucocorticoid GR receptors were 3.0 μg/ml and 12.6 μg/ml, respectively, both being within the range of BP-Cx-1 concentrations achievable in in vivo models.
Further, distribution of 3H labelled BP-Cx-1 in NIH3T3 murine fibroblasts and MCF7/R carcinoma cells was studied with autoradiography. 3H-BP-Cx-1 (visualized as silver grains produced by tritium beta particles) was mainly localized along the cell membrane, in the perinuclear region and in the nucleus, suggesting ability of BP-Cx-1 to enter cells and bind to membrane or cytosol receptors.
In our experiment, we observed the effect of BP-Cx-1 on maturation of dendritic cells (DCs): downregulation of expression of the lipid-presentation molecule CD1a, co-stimulatory molecules CD80, CD83 and CD 40, decreased production of pro-inflammatory cytokines IL-4 and TNF-α and increased production of anti-inflammatory cytokine IL-10. It is hypothesized that 3H-BP-Cx-1 detectable in the nucleus is part of the activated GR complex, known to be involved in regulation of transcription of genes responsible for the anti-inflammatory response. Based on IC50, cell distribution data and results of the experiment with DCs it is suggested that the in vivo effects of BP-Cx-1 are mediated via GR and 5-HT1 receptors thus promoting development of tolerogenic effector function in dendritic cells.
•Water-soluble fraction of wood lignin (BP-Cx-1) targets GR and 5-HT1 receptors.•3H-BP-Cx-1 is detectable on cell membranes, perinuclear region and cell nucleus.•Effects of BP-Cx-1 on dendritic cells resemble those of corticosteroids or serotonin.•BP-Cx-1 induces tol-DCs, reported to play a role in treatment of autoimmune diseases.
Time-resolved polarised fluorescence in flavin adenine dinucleotide (FAD) in water-propylene glycol mixtures has been studied as a function of propylene glycol concentration using the TCSPC ...technique. The fluorescence was excited by picosecond laser pulses either at 450 nm or at 355 nm, the wavelengths that belong to the first and second FAD absorption bands, respectively. The global fit procedure was used for the determination of fluorescence decay times, corresponding weighting coefficients, initial anisotropy and rotational diffusion time from experiment. The experimental data manifested a double-exponential decay in the whole range of propylene glycol concentrations with the decay times
$ \tau _1 $
τ
1
,
$ \tau _2 $
τ
2
and weighting coefficients
$ a_1 $
a
1
,
$ a_2 $
a
2
. The coefficients
$ a_1 $
a
1
and
$ a_2 $
a
2
and the corresponding relative fluorescence quantum yields
$ Q_{(1)rel} $
Q
(
1
)
r
e
l
and
$ Q_{(2)rel} $
Q
(
2
)
r
e
l
were shown to change dramatically with addition of propylene glycol to the solution and demonstrated the domination of contribution of longer decay time at medium and high propylene glycol concentrations. The rotational diffusion time
$ \tau _{rot} $
τ
r
o
t
manifested a sharp rise, up to 40 times with propylene glycol concentration that was practically proportional to solution viscosity. The initial anisotropy was determined to be equal to
$ r_0=0.35\pm 0.03 $
r
0
=
0.35
±
0.03
and
$ r_0=0.25\pm 0.02 $
r
0
=
0.25
±
0.02
under excitation at 450 nm and 355 nm, respectively. The dependence of fluorescence parameters on the solution viscosity and polarity was discussed taking into account FAD conformation distributions.
